Microscale distributed energy cogeneration method and system

ABSTRACT

A microscale energy cogeneration system includes at least a micro/nano-turbine set for converting fuel into mechanical energy, and a generator for converting mechanical energy produced by said micro/nano-turbine into electrical energy in the range of 1 to 5 kWh. The system further includes an exhaust passage downstream from said micro/nano-turbine delivering high temperature exhaust air from said micro/nano-turbine. At least one heat exchanger receives high temperature exhaust air from said exhaust passage for heat transfer. Said heat exchanger may be used to heat water and/or air of a house. A water heating system may be coupled to the heat exchanger for convening tap water into hot water and/or cool heating air into hot air. The portable micro/nano-turbine set may be scaled up by interconnecting several units at the same time and/or interconnecting different units of different users for balancing out the energy demand of those users.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

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INCORPORATION-BY-REFERENCE OF MATERIALS SUBMITTED ON A COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to energy generating systems. More specifically, the present invention relates to a microscale energy cogeneration system that can be used in a residential setting to supplement or substitute for a conventional utility electrical supply system and, further, can be used as part of an energy supply network. Even more particularly, the present invention is referred to a distributed energy cogeneration method with which it is possible to generate electricity and heat water and air.

2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.

Cogeneration is a highly efficient means of generating heat and electric power at the same time from the same energy source. Displacing fossil fuel combustion with heat that would normally be wasted in the process of power generation reaches efficiencies that can triple, or even quadruple, conventional power generation. In general, cogeneration systems are adapted to generate both electricity and heat from a single energy source. Such a cogeneration system can recover exhaust gas heat or waste heat of cooling water generated from an engine or turbine during an electricity generation operation, so that the cogeneration system can achieve an increase in energy efficiency of 70 to 80% over other systems.

By virtue of such an advantage, the cogeneration system has recently been highlighted as an electricity and heat supply source for buildings. In particular, the cogeneration system exhibits highly-efficient energy utilization in that the recovered waste heat is mainly used to heat/cool a confined space and to heat water. Although cogeneration has been in use for nearly a century, in the mid-1980s relatively low natural gas prices made it a widely attractive alternative for new power generation. In fact, gas-fired cogeneration is largely responsible for the decline in conventional power plant construction that occurred in North America during the 1980s. Cogeneration accounted for a large proportion of all new power plant capacity built in North America during much of the period in the late 1980s and early 1990s.

Cogeneration equipment can be fired by fuels other than natural gas. There are installations in operation that use wood, agricultural waste, peat moss, and a wide variety of other fuels, depending on local availability.

The environmental implications of cogeneration stem not just from its inherent efficiency, but also from its decentralized character. Because it is impractical to transport heat over any distance, cogeneration equipment must be located physically close to its heat user. A number of environmentally positive consequences flow from this fact: power tends to be generated close to the power consumer, reducing transmission losses, stray current, and the need for distribution equipment significantly. Cogeneration plants tend to be built smaller, and to be owned and operated by smaller and more localized companies than simple cycle power plants. As a general rule, they are also built closer to populated areas, which cause them to be held to higher environmental standards. In northern Europe, and increasingly in North America, cogeneration is at the heart of district heating and cooling systems. District heating combined with cogeneration has the potential to reduce human greenhouse gas emissions by more than any other technology except public transportation.

To understand cogeneration, it is necessary to know that most conventional power generation is based on burning a fuel to produce steam. It is the pressure of the steam which actually turns the turbines and generates power, in an inherently inefficient process. Because of a basic principle of physics, no more than one third of the energy of the original fuel can be converted to the steam pressure which generates electricity. Cogeneration, in contrast, makes use of the excess heat, usually in the form of relatively low-temperature steam exhausted from the power generation turbines. Such steam is suitable for a wide range of heating applications, and effectively displaces the combustion of carbon-based fuels, with all their environmental implications.

Today, existing electric generating technologies include large scale steam turbines producing electricity with a relatively low efficiency rate. The large scale steam turbines often emit undesirable byproducts, such as sulfur oxides, nitrous oxides, ashes, and mercury. Additionally, these large scale steam turbines release a large amount of heat, which is generally released into lakes often disrupting the environment.

More recently, it has been found that smaller scale turbines, such as microturbines, fueled by natural gas can operate with greater efficiency. During operation, the microturbines do not pollute to the same degree as large scale steam turbines and instead elements such as carbon dioxide and water are emitted, with only very low amounts of nitrogen oxides. Additionally, the heat recovery from operation of the microturbines is useful for heating water.

In many parts of the world there is a lack of electrical infrastructure. Installation of transmission and distribution lines to deliver the product to the consumer is very costly, especially in third world countries. Moreover, the electrical infrastructure in many countries is antiquated and overworked resulting in “brownouts” and “blackouts.” Consequently, there is a need for an energy generating system that can produce energy in a standalone system or that can be integrated into existing systems.

Even though there are several cogeneration systems in the market, all of them involve an important investment that makes this technology inaccessible for home owner users or portable applications. Also, it is very costly to escalate this type of systems, as the installation of several turbines together to supply a bigger demand or interconnecting a set of turbines for balancing out the generation of electricity in a determined area is not yet possible.

Therefore, even though the above cited technologies of the prior art address some of the energy generation needs of the market, a new, improved and economical microscale energy cogeneration system is still desired.

BRIEF SUMMARY OF THE INVENTION

This invention is directed to a microscale energy cogeneration system that can be used independently of a conventional utility electrical supply system or can be integrated into a conventional electrical supply system to supplement the system or contribute to the energy supply as part of a network.

In one form of the invention, a microscale energy cogeneration method includes the steps of converting the energy produced by the combustion chamber into mechanical energy and converting the mechanical energy produced by the turbine into electrical energy.

An important aspect of the present invention is a microscale energy cogeneration system designed to produce between 1 to 5 kWh, more particularly 1 to 3 kWh and more specifically 3 kWh using a portable and modular unit.

It is an object of the present invention to provide a microscale energy cogeneration system that is capable of heating tap water and heating air at the same time with high efficiency.

In another aspect of the invention, the generator may be an electric generator producing alternating electric current during the operation of the microscale energy cogeneration system. The fuel for the microscale energy cogeneration system may be natural gas, diesel, gasoline, and liquefied petroleum gas (LPG), among others.

According to another aspect of the invention, the microscale energy cogeneration system further includes an exhaust passage downstream from the microinano-turbine delivering high temperature exhaust air from the microinano-turbine and a heat exchanger receiving the high temperature exhaust air for heat transfer. A water heating system for converting tap water into hot water may be coupled to a heat exchange exhaust for releasing lower temperature exhaust air. The system is modular and portable and is able to generate electricity, hot water and hot air at the same time with efficiency higher than 85%.

In yet another aspect of the invention, the microscale energy cogeneration system may include another heat exchanger for coupling the present system to the heating system of a house.

In yet another aspect of the invention, the microscale energy cogeneration system may be scaled up to form a set of interconnected microinano turbines that can be used to provide the same user with more energy or to balance out the energy demand of a group of houses in a residential area.

In another aspect of the invention, the microscale energy cogeneration system may be portable or may be compatible for integration with a plurality of energy systems to provide the electrical distribution system with power and further may be configured for integration into a heating system, a cooling system and/or a water heating system.

Another aspect of the present invention provides a microscale energy cogeneration system that creates an energy source that produces efficient and clean electric energy, produces heat for heating, produces hot water, does not create pollution or vibrations, and does not need any maintenance over the years.

Also another aspect of this invention comprises a microscale energy cogeneration system that is smart, modular and portable, which can be managed remotely through Internet.

Also another aspect of this invention comprises a microscale energy cogeneration system that has a 3 kWh, 110/220 V AC, 12/24 VDC output, using different fuels including natural gas, diesel, gasoline and LPG.

Also another aspect of this invention consists of a microscale energy cogeneration system that generates electricity, 100 liters of hot water per hour, and hot air for heating a building.

In summary, the present invention is related to a microscale energy cogeneration method comprising the steps of:

-   -   (a) at least a micro/nano-turbine set for converting fuel into         mechanical energy, and a generator for converting mechanical         energy produced by said micro/nano-turbine into electrical         energy in the range of 1 to 5 kWh; further comprising an exhaust         passage downstream from said micro/nano-turbine delivering high         temperature exhaust air from said micro/nano-turbine; and     -   (b) at least one heat exchanger receiving high temperature         exhaust air from said exhaust passage for heat transfer; said         heat exchanger may be used to heat water and/or air of a house;         a water heating system may be coupled to the heat exchanger for         converting tap water into hot water and/or cool heating air into         hot air. The portable micro/nano-turbine set may be scaled up by         interconnecting several units at the same time and/or         interconnecting different units of different users for balancing         out the energy demand of those users.

Also, the present invention is related to a microscale energy cogeneration system comprising at least a micro/nano-turbine set and a generator set; an exhaust passage downstream from said micro/nano-turbine delivers high temperature exhaust air from said micro/nano-turbine; and at least one heat exchanger receiving high temperature exhaust air from said exhaust passage for heat transfer.

Also the present invention is related to a microscale distributed energy cogeneration method comprising the steps of:

-   -   (a) Connecting a fuel provider to a micro/nano turbine,     -   (b) Connecting the micro/nano turbine to a micro electric         generator;     -   (c) Connecting the micro electric generator to the electrical         grid of a facility.     -   (d) Connecting a heat exchanger apparatus to an exhaust passage         downstream from said micro/nano-turbine, and     -   (e) Connecting the heating system of the house to the heat         exchanger apparatus.

These and other aspects, features, and advantages of the present invention will become more readily apparent from the attached drawings and the detailed description of the preferred embodiments, which follow.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The preferred embodiments of the invention will hereinafter be described in conjunction with the appended drawings provided to illustrate and not to limit the invention, wherelike designations denote like elements, and in which:

FIG. 1 is general perspective view of the micro/nano-turbine used in the energy generating system in accordance with the present invention.

FIG. 2 is a front elevational view of the microinano-turbine of FIG. 1.

FIG. 3 is a right side elevational view.

FIG. 4 is a top plan view.

FIG. 5 is a left side elevational view.

FIG. 6 is a general perspective view of the energy generating system applied in a household application through which tap water and air may be heated using the exhausting gases of the micro/nano-turbine; and finally:

FIG. 7 is a schematic view of an energy generating system connected to the power grid with which the different energy generating systems may interact with the grid by taking energy if the particular application requires so, or may provide the grid with energy if the application is not requiring energy.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word “exemplary” or “illustrative” means “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” or “illustrative” is not necessarily to be construed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims.

Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also to be understood that the specific devices illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claim. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

The present invention is referred to an exemplary energy generating system comprising a micro/nano-turbine 100 with a modular and portable unit including a handle 102, a frontal portion 104 with a ventilation grill 106. Into said unit, a micro/nano-turbine is installed (not illustrated). Said micro/nano-turbine converts fuel into electrical power that can be used immediately, stored for later use, or delivered to a network for distribution within the network, such as an electric company grid. No specific details are provided regarding the structural parts of the turbine as they do not form part of the present invention. Any micro/nano turbine available in the market may be used.

The present nanoturbine energy generating system includes a combustion chamber, a micro/nano-turbine and a generator, such as an electric generator and inverter. The microscale energy cogeneration system may be portable and easily transportable between locations. Its general compact size, its light weight and the handle 102 are especially useful for that purpose. The micro/nano-turbine is preferably dimensioned such that it may be portable and has an output in a range to 1 to 5 kilowatts per hour and more preferably in a range of 2 to 4 kWh. In addition, the micro/nano-turbine 100 may be configured to have an efficiency of at least 70%, more preferably at least 80%, and more typically, in a range of 80% to 86%.

The present microscale energy cogeneration system is compatible for integration with other energy systems and systems requiring energy, as explained below.

Even though the general structure and functioning of a nano turbine is well known, we will provide some general technical information so as to give a general framework to this application.

Gaseous heat energy is provided to micro/nano-turbine 100, which converts the gaseous heat energy into mechanical energy. Then, a generator converts this mechanical energy into electrical energy. The electrical energy thus created may be supplied to the electrical grid of a house, to the electrical grid of a group of houses, to a boat, etc.

The generator as usual may include a rotating rotor and a stator. The rotor may be a permanent magnet positioned rotatably within the stator and rotates relative to the stator during the operation of micro/nano-turbine. Mechanical energy can be transferred to a shaft from micro/nano-turbine to the rotor, so that the shaft, the micro/nano-turbine and the rotor of said generator rotate in unison at speeds, for example, of up to 100,000 rpms or more.

The present microscale energy cogeneration system may be attached to a switchboard controller and meter. The switchboard controller and meter assists in the distribution of electric power to a building or location. Generally, the instant load from a microscale energy cogeneration system follows the controller of a standard home electrical box. The present nanoturbine energy generating system is easily compatible with all standard configurations for electrical box controllers.

As best seen in FIG. 6, the microscale energy cogeneration system may be additionally attached to the heating system 300 so that the exhaust heat of energy generating system 100 may be used in a heating system 300. The heating system 300 may include heat exchanger coupled to a heating duct and fan setup. The heat exchanger may use exhaust heat to provide exhaust heat and/or output heat for a location or building. The heat exchanger receives high temperature exhaust air from the exhaust passage downstream from the micro/nano-turbine 100 for heat transfer. In this manner, the microscale energy cogeneration system may assist with heating requirements for a location or building.

Additional components that may be added to the system 100 include a water system 200. With reference to FIG. 6, the exhaust heat of the heating system may be coupled to a water system 200. For example, the water system may comprise a hot water heater or water boiler and condenser to produce potable water. The water heater is connected to an exhaust heat 210-220 from heat exchanger. The water heater 200 receives water, and using the exhaust heat, produces hot water and optionally exhaust heat.

FIG. 7 is a schematic diagram of the microscale energy cogeneration system 100 connected to the electrical power grid 600. The system may also be controlled using the Transmission Control Protocol/Internet Protocol (TCP/IP) network 400 through a control center 500. Accordingly, the microscale energy cogeneration system 100 may take energy from the grid 600 if necessary, or provide energy to the grid 600 if the consumption of the local system is lower than the energy produced by it. The main feature of the present system comprises its ability to scale up by connecting several units for the same user, or several units may be interconnected as a grid for balancing out the energy demand of a specific set of users.

As generally noted above, the energy system 100 may be integrated into a house, to supplement or substitute an existing energy system. It should be noted that the energy system can be integrated into all types and sizes of buildings and structures as well as locations requiring energy. As would be understood, the system 100 may either include fewer components and systems or may include additional components or systems.

The energy system 100 can integrate any one or more of the heating, cooling, water heating and electrical systems into a mobile and portable unit. As would be understood from the above description, the energy system 100 is powered by different types of fuel. Using nano/microscale energy cogeneration system 100, energy system can fulfill the electrical, heating, cooling and/or hot water, and/or potable water needs for a location, building or structure. It may also be used for hybridizing cars, boating power, outdoor applications, and home use applications.

The home energy system 100 can provide at least part of, if not all the electrical needs of a single location, structure or building, such as house. The energy system 100 is integrated with the grid 600 at a junction box or switchboard controller and meter to distribute electrical load in a location. Either the energy system or grid 600 can be the primary system with the other system serving as an auxiliary or support system. When the energy system produces more electricity than required, the electrical load can be stored in a storage device, such as some type of battery, or returned back to the power grid 600. In systems that are not connected to the electric company, like a system setup located in a remote location, surplus electrical load can be delivered to a specific location over a local grid 600. Alternatively, if surplus electrical load is returned to the grid 600, a house with surplus electricity can designate a specific house or location to receive the electrical load through the electric company's grid. This sharing of electrical loads allows two locations to exchange electrical loads at a cost lower than purchasing from the electric company.

The present system has several applications, including but not limited to:

-   -   (a) Hybridization of electric vehicles     -   (b) Domestic production of power and heat     -   (c) Smart power grids     -   (d) Boating power and heat supply     -   (e) Outdoor applications

It will be understood that the embodiments shown in the drawings and described above are merely for illustrative purposes, and are not intended to limit the scope of the invention, which is defined by the claims, which follow as interpreted under the principles of patent law including the Doctrine of Equivalents. 

1. A microscale distributed energy cogeneration system comprising at least a portable energy cogeneration unit including at least a micro/nano-turbine set and a micro electric generator set, an exhaust passage downstream from said micro/nano-turbine delivering high temperature exhaust air from said micro/nano-turbine, and at least one heat exchanger receiving high temperature exhaust air from said exhaust passage for heat transfer.
 2. A microscale distributed energy cogeneration system in accordance with claim 1, wherein the heat exchanger heats water and/or air of a house.
 3. A microscale distributed energy cogeneration system in accordance with claim 1, wherein several portable energy cogeneration units are interconnected as a set and/or different individual units of different users are interconnected balancing out the energy demand of those users.
 4. A microscale distributed energy cogeneration system in accordance with claim 3, a portable and modular unit is created by interconnecting individual units capable of producing between 1 to 5 kWh, more particularly 1 to 3 kWh and more specifically 3 kWh.
 5. A microscale distributed energy cogeneration system in accordance with claim 1, wherein the heat exchanger heats tap water and air at the same time.
 6. A microscale distributed energy cogeneration system in accordance with claim 1, wherein the generator is an electric generator producing alternating electric current during operation of the microscale energy cogeneration system.
 7. A microscale distributed energy cogeneration system in accordance with claim 1, wherein the fuel for the microscale energy cogeneration system is one of natural gas, diesel, gasoline, and LPG.
 8. A microscale distributed energy cogeneration system in accordance with claim 1, wherein the microscale energy cogeneration system includes an exhaust passage downstream from the micro/nano-turbine delivering high temperature exhaust air from the micro/nano-turbine and a heat exchanger receiving the high temperature exhaust air for heat transfer.
 9. A microscale distributed energy cogeneration system in accordance with claim 8, wherein a water heating system for converting tap water into hot water may be coupled to a heat exchange exhaust for releasing lower temperature exhaust air.
 10. A microscale distributed energy cogeneration system in accordance with claim 9, wherein the system is modular and portable and generates electricity, hot water and hot air at the same time with efficiency of at least 85%.
 11. A microscale distributed energy cogeneration system in accordance with claim 1, wherein the microscale energy cogeneration system includes another heat exchanger for coupling the present system to the heating system of a house.
 12. A microscale distributed energy cogeneration system in accordance with claim 1, wherein the microscale energy cogeneration system forms a set of interconnected micro/nano turbines to provide the same user more energy to or for balancing out the energy demand of a group of houses in a residential area.
 13. A microscale distributed energy cogeneration system in accordance with claim 1, wherein the microscale energy cogeneration system is managed remotely by connecting the controls of the system with a mini PLC through Internet.
 14. A microscale distributed energy cogeneration method comprising the steps of: connecting a fuel provider to a micro/nano turbine; connecting the micro/nano turbine to an micro electric generator; connecting the micro electric generator to the electrical grid of a facility; connecting a heat exchanger apparatus to an exhaust passage downstream from said micro/nano-turbine; and connecting the heating system of the house to the heat exchanger apparatus.
 15. A microscale distributed energy cogeneration method in accordance with claim 14, wherein the generator includes a rotating rotor and a stator, the rotor is a permanent magnet positioned rotatably within the stator and rotates relative to the stator during operation of micro/nano-turbine.
 16. A microscale distributed energy cogeneration method in accordance with claim 14, wherein the shaft of the micro/nano-turbine and the rotor of said generator rotate in unison.
 17. A microscale distributed energy cogeneration method in accordance with claim 14, wherein the heating system is connected to a water system of a facility, the water system comprising a hot water heater, a water boiler and a condenser to produce potable water.
 18. A microscale distributed energy cogeneration method in accordance with claim 14, wherein several micro/nano turbines, heat exchangers and electric generator sets are connected for the same facility.
 19. A microscale distributed energy cogeneration method in accordance with claim 14, wherein several micro/nano turbines, heat exchangers and electric generator sets are connected to several houses interconnected as a grid for balancing out the energy demand of a specific set of facilities.
 20. A microscale distributed energy cogeneration method in accordance with claim 14, wherein the facility is one of the following: a house, a boat, a group of houses, a small building.
 21. A microscale distributed energy cogeneration method, wherein at least two portable energy cogeneration units are combined and connected to a power grid to add power.
 22. A microscale distributed energy cogeneration method, in accordance with claim 21, wherein the portable energy cogeneration units are combines and connected to one of the following functions to a facility: hot air, hot water, cool air, power. 